Heat exchanger



Nov. 2 1926.

J. PRIMROSE HEAT EXCHANGER 2 Sheets-Sheet 1- Filed March 23 [a INVENTOR ATTORNEY Nov. 2 1926.

J. PRIMROSE HEAT EXCHANGER Filed March 23 1923 2 Sheets-Sheet f7 INVENTOR MM ATTORNEY (A i In Patented Nov. 2, 1926,.

.- UNITED STATES IPA-TENT OFFICE.

JOHN IE'IEtIIItIIZl'v-SOSE, OF RICHMOND, NEW YORK, ASSIGNOIt T0 POWER SPECIALTY COM- 'PANY, OF LEEW YORK, N. Y., A COIjtPOB-ATION OF NEW YORK.

- HEAT nxcnanenn.

Application filed March 23, 1923. Serial No. 627,169.

My present invention consists in improvements in heatexchangers of the type com: prisin a plurality of tubular elements arrange side by side and each comprising an inner tube and an outer tube which is larger in internal diameter than the external diameter of the inner tube, and connections passed in series through the annular spaces between the inner and outer tubes of ous tubular elements.

The general object of my invention is to provide improved end connections for the tunlar elements of a heat exchanger of the varitype specified, and my invention is characterized by the simplicity and efiectiveness of the end connections, and a relative ease with which they permit theapparatus in which they are used to be assembled and taken vapart when necessary for cleaning or repairs and by the fact that the tubular elements of a single heat exchanger are arranged ingroups, any one of which may be readily cut out of service for cleaning, inspection or repairs, or to reduce thev flow capacity of the heat exchanger as a whole.

The variousfeatures of novelty which characterize my invention are pointed out I with particularity. in the claims annexed to and forming a part of this specification.- For a better understanding of the invention, however, its advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descrip tive matter in which I have illustrated and described a preferred embodiment of my in-" vention.

Of the drawings:

F-'g.-1 is an elevation of a heat er, in section on the'line -11of Fig. 2;

Fig. 2 is an elevation partly in section on the line 2*2 of Fig. 1;

Fig. 3 is a section taken similarly to Fig.

1, but on a larger scale, and illustrating thetube connections employedat one end of the heat exchanger,

Fig. 4is a View similar to Fig. 3 illustrating the tube connections at the opposite end of .the heat exchanger,

Fig. 5 is a partial section on the line 5-5 of Fig. 4; and

Fig. 6 is a partial section on the line 6-6 of Fig. 5.

The heat exchanger shown in the drawings comprises a plurality of tubular elements, each consisting of an outer tube A, surrounding an inner tube a, the external diameter of which is less than the internal diameter'of the outer tube. The tubular elements are arranged inrows or sections, each comprising a plurality of elements connected in pairs at opposite. ends of the exchanger, and forming a separate, and separately usable section or unit, as hereinafter explained. The tubular element at each end of each row or section, is connected to a.

corresponding chambered member B. The latter is; formed with an opening B in its wall in which the end of the outer tube of the corresponding element is secured with the bore' of said tube in open communication with the chamber B 'of the member The corresponding inner tube a of the element, extends through the chambenB surrounding it; The chamber space B in elements is connected by a valve EA to a the member B at one end of each row of header FA, and the. interior of the eorrespending tube a is'connected by the tubular part B and a va'lve C to a header D. The space B in the member, B at the opposite to Y j end of the section i connected by a valve" exchang- Eto aheader F, and. it's tubular art B is connected by avalve CA to a-hea er DA. I

At the opposite end of the exchanger from that at which the headers B are located, the

outer tubes A of the diflerent elements are connected in pairs by headers G. Each header G is in the form of a box havin a removable ihead G at its outer end, an "havg p r r G? at its inner end in which 00 and also serve to provide strengthening metal i013 G an 18 themethod employed in the heat exthe outer tubes of the connected elements are secured. The two inner tubes (1 of the two elements having their outer tubes A Connected by a header G are connected by a device in the form of a return bend member H located within the corresponding header G. In the open ends of the header H the ends of the tubes a are suitably secured as by welding, or by a threaded connection, the

threaded. connection being preferably empermit of freedom for the thermal elongation and. contraction of the inner tubes re tive to the outer tubes, each return bend H is advantageously formed with a bearing rim H which loosely fits between bearing surfaces G 'provided for the purpose atthe outer end of the chamber in the corresponding member G. As shown, these bearing surfaces comprise extensions G" formed by the inner surfaces of'finger-like portions of the member G, which extend into the enlarged portion of the chamber in the member G,

adjacent the holes formed in the member for the bolts securing the header G in place.

At the opposite end of the heat exchanger from that at which the headers G are 10- cated, the intermediate tubular elements are connected in pairs by means of inner boxp likeheaders HA and outer headers GA.

lar elements of the heat exchanger are en cased in insulating material J, an additional, insulation K is provided to encase the bank of tubes as a whole. Additional insulation may be provided at the endsof the heat exchanger, if desired, to cover the otherwise exposed portions of the tubular elements and the connections thereto. The tubular elements are supported by apertured tube sheets S and S, and a structural metal framework.

The heat exchanger in the particular form shown, was primarily designed for use inv transferring heat from a relatively hot liquid supplied through the header D and passing. in series through the tubes a into the header DA, to a relatively coolliquid supplied through the header F and passing through the intertube spaces of the connected elements to the headers FA. It will be apparent, however, that either fluid may be a liquid or a gas, and that it is not highly important whether the fluid in the tubes 0, or

the fluid in the intertube space is the hotter.

V The construction described is obviously simple, efiect-ive and durable from a mechanical standpoint, and the apparatus as a whole is adapted to accommodate the relative expansion and contraction of the parts resulting, from relative changes in temperature. 1

An important characteristic of the invention is the ease with which the apparatus may be initially assembled, and may be disassembled, in whiole or in part, and reassemble'd when necessary for cleaning or repairs, or for other purposes.

- In assembling the apparatus the outer tubes A of the various tubular elements are first secured in the corresponding headers G and GA, and chambered members B, and it will be apparent that it is readily possible to secure each end of each of the outer tubes in rolling or expanding it in place as boiler tubes are ordinarily secured in boiler tube sheets. This is ordinarily the most satisfacmethod of securing such parts together,

changer shown. The tubes a are connected to the return bends or headers H before being inserted in the outer tubes of the tubularelements of which they are to form a art. After the tubes a are secured to the return bends H, they are put in place in the apparatus, and the opposite ends of the tubes a are then secured, preferably by expanding or rolling them, in the headers HA and members B. If and when it becomes necessary to remove any tube a, this canbe effected by first detaching that tube, and the tube a connected toit by the corresponding header H, from the chambered member B and header HA or the headers HA at the opposite end of the apparatus to which those tubes are connected. The tubes a may be thus detached by cutting them away, or in other ways in which boiler and analogous tubes are separated from tube sheets and the rality of tubular elements arranged side by I tion of the like the headers HA in place of the single portion of the exchanger left in service. v

It is possible, of course, to use headers return bends H.- The latter offer the advantages, however, that the frictional resistance to flow through such return bends is generally, appreciably less, than the resistance rality of side by side tubular elements each to flow througha header like the headers. ,HA, and the return bend; is less expensive appended claims, and that some features of 'my invention may sometimes be used to advantage ifivithout a corresponding use of other features} A Having now described my invention, what I claim as new and desireto' secure by Letters Patent, is: v

1. In a heat exchanger comprising a plucomprising an inner tube and an outer tube the internal diameter of which is greater than-the external diameter of the inner'tube,

headers connecting each outer tube at one 1 end to the adjacent end of another outer tube and at its other end to the adjacent end of a third tube, and connecting devices located one within each of the, first mentioned headers and connecting the two corresponding inner tubes, said headers having headseach removable to permit access to,

" and the removal of the corresponding con necting device. 7 i

2. In a heat exchanger comprising a plurality o ttubular elements each comprising an inner tube and an outer tube the internal diameter of which is greater than the external diameter .of the inner tube, headers togetherm pairs, and connectin connectingadjacent endsof the outer tubes devices locatedlone within each of the rst men-' tioned headers and connecting the corresponding inner tubes, each header and the device enclosed by it being relativel shaped .to provide a flow path between t ejnter tube'spa'ceslof the two tube elements and to permit relative axial movement of the innerand outer tubesof theconnected memwitli respect to the outer tubes.

hers while holding the innertubes centrally;

. .3. In aheat exchanger comprising a pluside and each comprising an inner tube and v x an outer tube the-internalfdiameter of which j is greater than the-external. diameterof the inner tube, headersconnecting adjacent ends within each of the of the outer tubes together in pairs, each of]. said headers being formed with a removable devices located .one rst mentioned headers head, and connectin and connecting the corresponding inner '10 tubes, the said connecting devices at one end of the heat exchanger having tube openings for the various tubes connected-thereto'and 1 other openings through which the various" tubes connected thereto may be expanded into the correspondingtubeb enings, and removable means for closing t e last men-' tioned openings.

4. In a heat exchanger comprising afplurality of tubular element-s arranged side by side and each-comprising an inner tube and an outer tube the internal diameter of which is greater than the external diameter of the inner tube, headers connecting adjacent ends of the outer tubes together in pairs, and into .each of which the ends of the outer tubes connected by it are expanded, each of said headers being formed with a removable head, and connecting devices located one within.

each of the first mentioned headers and connecting the correspondingimier tubes, said devices atoneend of the apparatus being each formed with hand hole openings and having the ends of the inner tubes which it connects secured thereto by expanding them into place.

I 5. In a heat exchangercomprising a .pIurality of tubular elements each "comprising an inner tube and an outer tube theinternal diameter of which is greater than the .ex-

ternal diameter of the inner tube, headers connecting adjacent ends of the outer tubes together in airs, and connecting devices located one within each of the first mentioned headers and connecting the corresponding inner tubes, each header and the device enj closed by it bein relatively shaped to provide a flow pat l between theinter-tube I spaces of the-two tube elements and to pro vide coacting bearing surfaces at the outer, 11o

end of said device and on the adjacent portion of the header permitting relative axial movement. of the inner and outer tubes of the connected members while holding the inner tubes centrally with res peet". .to' 1 the outer tubes.

6. A heat exchanger comprisingi'ia plus.

rality of tubular elements arrange jsideby side and each comprising an inner tube and an outer tubethe internaldiameter of which. is greater than the external diameter- 0f the 4 inner tube, means connecting :the intertube 'bes are expanded and each having a "re- .v m vable' head and serving to 'cohnect two outer tubes, connecting devicesat one end spaces of the elements ,for series flow] therethrough, comprising headers, having" tube: a

openings into which the ends of the outer,125

of the exchanger each connecting one vend .offea'eh inner tub'ej toithe corresponding end of another inner tube and each located in tube holes and normally closed hand hole a corresponding header and with its attached openings and each having the ends of two tubes insertable in and removable from said inner tubes expanded in its tube holes.

header when the removable head of the lat-'v Signed at New York in the county of New ter is removed and connecting devices for York and State of New York this 20th day the inner tube: at the opposite end of the of March A. D. 1923.

exchanger, each located in a corresponding a connecting header and formed with two JOHN PRIMROSE 

